ATOMIC LAYER EPITAXY OF CDTE ON GAAS, BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

In this paper, we report on the atomic layer epitaxy (ALE) of CdTe on GaAs by the organometallic vapor phase epitaxial process. Self-limiting growth at one monolayer was obtained over the temperature range from 250-degrees-C to 320-degrees-C, under a wide range of reactant pressure conditions. A study of growth mechanism indicates that the decomposition of DMCd into Cd is the rate limiting step at and below 250-degrees-C, and the Te precursors decompose catalytically on the Cd covered surface. We have used this ALE grown layer to improve the properties of conventionally grown CdTe on GaAs. A significant improvement in the morphology and crystal quality was observed when the initial CdTe nucleation step was carried out using the ALE method, prior to the deposition of CdTe by the conventional method.